Process for the preparation of fluorescent pigments

ABSTRACT

Compounds of formula 
     
         A(B).sub.x,                                                (I), 
    
     wherein x is an integer from 1 to 4, 
     A is the radical of a chromophore of the quinacridone, anthraquinone, perylene, indigo, quinophthalone, isoindolinone, isoindoline, dioxazine, phthalocyanine or azo series, which radical contains x N-atoms attached to B, preferably with at least one directly adjacent or conjugated carbonyl group, 
     B is a group of formula ##STR1## and, if x is 2, 3 or 4, may also be one, two or three hydrogen atoms. The symbols Q, R 1 , R 2 , R 3 , R 4 , X, Y, Z, m and n, are as defined in claim 1. 
     These carbamate group-containing soluble chromophores are distinguished by outstanding solid state fluorescence in the UV range as well as the by ease with which they can be converted to the corresponding pigments in the substrate in which they are incorporated.

CONTINUING DATA AS CLAIMED BY APPLICANT

This application is a division of application Ser. No. 08/677,287, filedJul. 9, 1996, now U.S. Pat. No. 5,780,627, which is a division ofapplication Ser. No. 08/319,399, filed Oct. 6, 1994, now U.S. Pat. No.5,561,232.

The present invention relates to novel soluble chromophores containingcarbamate groups, to their preparation and to the use thereof asfluorescent pigments and as pigment precursors which can be readilyconverted into the corresponding pigments.

N-substituted pyrrolo[3,4-c]pyrroles are disclosed in U.S. Pat. Nos.4,585,878 and 4,791,204. From the generic definition of all substituentsit can be inferred that the N-substituents may also be, inter alia,alkoxycarbonyl groups, which are defined in U.S. Pat. No. 4,791,204 asincluding methoxycarbonyl, ethoxycarbonyl, n-propoxycarbonyl,n-butoxycarbonyl and n-hexyloxycarbonyl. U.S. Pat. No. 4,585,878 teachesthat the N-substituted pyrrolo[3,4-c]-pyrroles disclosed therein exhibithigh fluorescence in dissolved form in polymers.

The invention provides novel carbamate group-containing solublechromophores which, surprisingly, exhibit a very high solid statefluorescence, especially in the UV range, and which are readilyconvertible into the corresponding pigments with simultaneousdisplacement of the absorption spectrum, and hence open the way tounexpected applications.

Accordingly, the invention relates to compounds of formula

    A(B).sub.x,                                                (I),

wherein x is an integer from 1 to 4,

A is the radical of a chromophore of the quinacridone, anthraquinone,perylene, indigo, quinophthalone, isoindolinone, isoindoline, dioxazine,phthalocyanine or azo series, which radical contains x N-atoms attachedto B, preferably with at least one directly adjacent or conjugatedcarbonyl group,

B is a group of formula ##STR2## and, if x is 2, 3 or 4, may also beone, two or three hydrogen atoms, in which formulae (II), (III) and (IV)

m, n and p are each independently of one another 0 or 1,

X is C₁ -C₁₄ alkylene or C₂ -C₈ alkenylene,

Y is a group --V--(CH₂)_(q) --,

Z is a group --V--(CH₂)_(r) --,

V is C₃ -C₆ cycloalkylene,

q is an integer from 1 to 6, and

r is an integer from 0 to 6,

R₁ and R₂ are each independently of the other hydrogen, C₁ -C₆ alkyl, C₁-C₄ alkoxy, halogen, CN, NO₂, unsubstituted phenyl or phenoxy or phenylor phenoxy which are substituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy orhalogen,

Q is hydrogen, CN, Si(R₁)₃, is a group C(R₅)(R₆)(R₇),

wherein R₅, R₆ and R₇ are each independently of one another hydrogen orhalogen and at least one of R₅, R₆ and R₇ is halogen,

a group ##STR3## wherein R₁ and R₂ are as defined above, a group SO₂ R₈or SR₈, wherein R₈ is C₁ -C₄ alkyl,

is a group CH(R₉)₂, wherein R₉ is unsubstituted phenyl or phenyl whichis substituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy or halogen, or

is a group of formula ##STR4## R₃ and R₄ are each independently of theother hydrogen, C₁ -C₁₈ alkyl, a group ##STR5## wherein X, Y, R₁, R₂, mand n are as defined above, or R₃ and R4, together with the linkingnitrogen atom, form a pyrrolidinyl, piperidinyl or morpholinyl radical.

A is the radical of a known chromophore having the basic structure

    A(H).sub.x,

for example ##STR6## and all known derivatives thereof.

X in the significance of C₁ -C₁₄ alkylene is straight-chain or branchedalkylene, typically methylene, dimethylene, trimethylene,1-methylmethylene, 1,1-dimethylmethylene, 1,1-dimethyldimethylene,1,1-dimethyltrimethylene, 1-ethyldimethylene,1-ethyl-1-methyldimethylene, tetramethylene, 1,1-dimethyltetramethylene,2,2-dimethyltrimethylene, hexamethylene, decamethylene,1,1-dimethyldecamethylene, 1,1-diethyldecamethylene ortetradecamethylene.

X in the significance of C₂ -C₈ alkenylene is straight-chain or branchedalkenylene, typically vinylene, allylene, methallylene,1methyl-2-butenylene, 1,1-dimethyl-3-butenylene, 2-butenylene,2-hexenylene, 3-hexenylene or 2-octenylene.

Halogen substituents may be iodo, fluoro, preferably bromo and, mostpreferably, chloro.

C₁ -C₆ Alkyl will typically be methyl, ethyl, n-propyl, isopropyl,n-butyl, sec-butyl, tert-butyl, n-amyl, tert-amyl, hexyl, and C₁ -C₁₈alkyl may additionally be heptyl, octyl, 2-ethylhexyl, nonyl, decyl,dodecyl, tetradecyl, hexadecyl or octadecyl.

C₁ -C₄ Alkoxy is typically methoxy, ethoxy, n-propoxy, isopropoxy orbutoxy.

C₃ -C₆ Cycloalkylene is typically cyclopropylene, cyclopentylene and,preferably, cyclohexylene.

Particularly interesting compounds of formula I are those wherein x is 1or 2 and B is a group of formula ##STR7## and, if x is 2, may also beone hydrogen atom, and in formulae IV, V and VI

m is 0 or 1,

X is C₁ -C₄ alkylene or C₂ -C₅ alkenylene,

R₁ and R₂ are each independently of the other hydrogen, C₁ -C₄ alkyl,methoxy, chloro or NO₂, and

Q is hydrogen, CN, CCl₃, a group ##STR8## SO₂ CH₃ or SCH₃, R₃ and R₄ areeach independently of the other hydrogen, C₁ -C₄ alkyl or a group##STR9## or R₃ and R₄, taken together, form a piperidinyl radical, andpreferably those wherein x is 2 and B may be twice a group of formula##STR10##

Preferred compounds of formula I are

a) perylenecarboximides of formula ##STR11## wherein D is hydrogen, C₁-C₆ alkyl, unsubstituted or halogen- or C₁ -C₄ alkyl-substituted phenyl,benzyl or phenethyl, or is B,

b) quinacridones of formula ##STR12## wherein R₁₀ and R₁₁ are eachindependently of the other hydrogen, halogen, C₁ -C₁₈ alkyl, C₁ -C₄alkoxy or phenyl,

c) dioxazines of formula ##STR13## wherein R₁₂ is hydrogen, halogen orC₁ -C₁₈ alkyl, d) isoindolines of formulae ##STR14## wherein R₁₃ is agroup ##STR15## R₁₄ is hydrogen, C₁ -C₁₈ alkyl, benzyl or a group##STR16## R₁₅ has the same meaning as R₁₃, R₁₆, R₁₇, R₁₈ and R₁₉ areeach independently of one another hydrogen, C₁ -C₁₈ alkyl, C₁ -C₄alkoxy, halogen or trifluoromethyl,

e)indigo derivatives of formula ##STR17## wherein R₂₀ is hydrogen, CN,C₁ -C₄ alkyl, C₁ -C₄ alkoxy or halogen,

f) azo compounds of formula ##STR18## wherein R₂₁ and R₂₂ are eachindependently of the other hydrogen, halogen, C₁ -C₄ alkyl or C₁ -C₄alkoxy,

g)anthraquinoid compounds of formula ##STR19## and h) phthalocyanines offormula ##STR20## wherein X₁ is H₂, Zn, Cu, Ni, Fe or V,

X₂ is --CH(R₂₄)-- or --SO₂ --

R₂₃ is hydrogen, C₁ -C₄ alkyl, --N(E)R₂₄, --NHCOR₂₅, --COR₂₅ or##STR21## R₂₄ is hydrogen or C₁ -C₄ alkyl, R₂₅ is C₁ -C₄ alkyl and R₂₆is hydrogen, halogen, C₁ -C₄ alkyl or C₁ -C₄ alkoxy,

z is 0 or 1 and y is an integer from 1 to 4, in each of which formulae Eis hydrogen or is B, with the proviso that E in each formula is at leastone group B and B is as defined above, in respect of which definitionthe preferred meanings cited above apply.

Among the phthalocyanines, those of formula XVI, wherein X₁ is H₂, Cu orZn, X₂ is --CH₂ -- or --SO₂ --, R₂₃ is hydrogen, --NHCOCH₃ or benzoyland z is 1, are preferred.

In U.S. Pat. No. 4,585,878 it is said in connection with the preparationof N-unsubstituted pyrrolpyrroles that they can be obtained by reactinga N-substituted pyrrolo-3,4-c-pyrrole with a compound that carries thecorresponding N-substituents as leaving groups in an organic solvent. Inthe sole Example describing a compound containing a N-carbonyl groupExample 9: N-benzoyl), 1,4 diketo-3,6diphenyl-pyrrolo[3,4-c]pyrrole isreacted with benzoyl chloride. In the experiment to prepare the desiredcarbamates in analogous manner by reaction with a corresponding acidchloride derivative, it was unfortunately found that it was onlypossible to obtain said carbamates in poor yield.

Very surprisingly, however, it was observed that when using appropriatetrihaloacetates, azides, carbonates, alkylidene-iminooxyformates or, inparticular, appropriate dicarbonates, the desired carbamates areobtained in very good yield. An improved yield is also obtained--even ifonly to a lesser degree--by carrying out the reaction with an aliphaticacid chloride derivative, conveniently butyl chloroformate, in thepresence of a base as catalyst.

Accordingly, the invention further relates to a process for thepreparation of compounds of formula I, which comprises reacting acompound of formula

    A(H).sub.x,                                                (XVII)

wherein A and x are as defined above, in the desired molar ratio with adicarbonate of formula

    B--O--B                                                    (XVIII)

or with a trihaloacetate of formula

    (R.sub.27).sub.3 C--B                                      (XIX),

or with an azide of formula

    BN.sub.3                                                   (XX),

or with a carbonate of formula

    B--OR.sub.28                                               (XXI),

or with an alkylidene-iminooxyformate of formula ##STR22## wherein B isas defined above, R₂₇ is chloro, fluoro or bromo, R₂₈ is C₁ -C₄ alkyl orunsubstituted phenyl or phenyl which is substituted by halogen, C₁ -C₄alkyl, C₁ -C₄ alkoxy or --CN, R₂₉ is --CN or --COOR₁₈, and R₃₀ isunsubstituted phenyl or phenyl which is substituted by halogen, C₁ -C₄alkyl, C₁ -C₄ alkoxy or --CN, in an aprotic organic solvent and in thepresence of a base as catalyst, conveniently in the temperature rangefrom 0 to 400° C., preferably from 10 to 200° C., for 2 to 80 hours.

It is preferred to react the compound of formula XVII with a dicarbonateof formula XVIII.

The compounds of formula XVII, dicarbonates of formula XVIII,trihaloacetates of formula XIX, azides of formulae XX, carbonates offormula XXI and alkylidene-iminooxyformates of formula XXII are knownsubstances. Any that are novel can be prepared by methods analogous tostandard known ones.

The respective molar ratio of the compound of formula XVII and thecompounds of formulae XVIII-XXII will depend on the meaning of x, i.e.on the number of groups B to be introduced. Preferably, however, thecompounds of formulae XVIII-XXII will be used in a 2- to 10-fold excess.

Suitable solvents are typically ethers such as tetrahydrofuran ordioxane, or glycol ethers such as ethylene glycol methyl ether, ethyleneglycol ethyl ether, diethylene glycol monomethyl ether or diethyleneglycol monoethyl ether, and also dipolar aprotic solvents such asacetonitrile, benzonitrile, N,N-dimethylformamide,N,N-dimethylacetamide, nitrobenzene, N-methylpyrrolidone, halogenatedaliphatic or aromatic hydrocarbons such as trichloroethane, benzene oralkyl-, alkoxy- or halogen-substituted benzene, typically includingtoluene, xylene, anisole or chlorobenzene, or aromatic N-heterocyclessuch as pyridine, picoline or quinoline. Preferred solvents aretypically tetrahydrofuran, N,N-dimethylformamide andN-methylpyrrolidone. The cited solvents may also be used as mixtures. Itis convenient to use 5-20 parts by weight of solvent to 1 part by weightof reactant.

Bases suitable as catalysts are typically the alkali metals themselves,conveniently lithium, sodium or potassium and the hydroxides orcarbonates thereof, or alkali metal amides such as lithium, sodium orpotassium amide or alkali metal hydrides such as lithium, sodium orpotassium hydride, or alkaline earth metal or alkali metal alcoholateswhich are derived in particular from primary, secondary or tertiaryaliphatic alcohols of 1 to 10 carbon atoms, for example lithium, sodiumor potasssium methylate, ethylate, n-propylate, isopropylate,n-butylate, sec-butylate, tert-butylate, 2-methyl-2-butylate,2-methyl-2-pentylate, 3-methyl-3-pentylate, 3-ethyl-3-pentylate, andalso organic aliphatic aromatic or heterocyclic N-bases, typicallyincluding diazabicyclooctene, diazabicycloundecene and4-dimethylaminopyridine and trialkylamines such as trimethylamine ortriethylamine. A mixture of the cited bases may also be used.

The organic nitrogen bases are preferred, for examplediazabicyclooctene, diazabicycloundecene and preferably,4-dimethylaminopyridine.

The reaction is preferably carried out in the temperature range from 10to 100° C., most preferably from 14 to 40° C., and under atmosphericpressure.

The novel compounds of formula I are admirably suitable for use asfluorescent pigments for the mass colouration of organic material ofhigh molecular weight.

Illustrative examples of high molecular weight organic materials whichcan be coloured with the novel compounds of formula I are vinyl polymerssuch as polystyrene, poly-α-methylstyrene, poly-p-methylstyrene,poly-p-hydroxystyrene, poly-p-hydroxy-phenylstyrene,poly(methylacrylate) and poly(acrylamide) as well as the correspondingmethacrylic compounds, poly(methylmaleate), poly(acrylonitile),poly(methacrylonitrile), poly(vinyl chloride), poly(vinyl fluoride),poly(vinylidene chloride), poly(vinylidene fluoride), poly(vinylacetate), poly(methyl vinyl ether) and poly(butyl vinyl ether); novolaksderived from C₁ -C₆ aldehydes, typically formaldehyde and acetaldehyde,and a binuclear, preferably mononuclear, phenol which may be substitutedby one or two C₁ -C₉ alkyl groups, one or two halogen atoms or a phenylring, for example o-, m- or p-cresol, xylene, p-tert-butyl phenol, o-,m- or p-nonylphenol, p-chlorophenol or p-phenylphenol, or from acompound containing more than one phenolic group, e.g. resorcinol,bis(4-hydroxyphenyl)methane or 2,2-bis(4-hydroxyphenyl)propane; polymersderived from maleimide and/or maleic anhydride, e.g. copolymers ofmaleic anhydride and styrene; poly(vinylpyrrolidone), biopolymers andderivatives thereof such as cellulose, starch, chitine, chitosane,gelatin, zein, ethyl cellulose, nitrocellulose, cellulose acetate andcellulose butyrate; natural resins and synthetic resins such as rubber,casein, silicone and silicone resins, ABS, urea/formaldehyde andmelarine/formaldehyde resins, alkyd resins, phenolic resins, polyamides,polyimides, polyamidefimides, polysulfones, polyether sulfones,polyphenylene oxides, polyurethanes, polyureas, polycarbonates,polyarylenes, polyarylene sulfides, polyepoxides, polyolefins andpolyalkadienes. Preferred high molecular weight organic materials aretypically cellulose ethers and esters, for example ethyl cellulose,nitrocellulose, cellulose acetate or cellulose butyrate, natural resinsor synthetic resins such as polymerisation or condensation resins, forexample aminoplasts, in particular urea/formaldehyde andmelamine/formaldehyde resins, alkyd resins, phenolic plastics,polycarbonates, polyolefins, polystyrene, polyvinyl chloride,polyamides, polyurethanes, polyesters, ABS, polyphenylene oxide, rubber,casein, silicone and silicone resins, singly or in mixtures.

The above high molecular weight organic compounds may be singly or asmixtures in the form of plastic materials, melts or of spinningsolutions, paint systems, coating materials or printing inks. Dependingon the end use requirement, it is expedient to use the novel compoundsof formula I as toners or in the form of preparations.

The novel compounds of formula I are particularly suitable for the masscoloration of polyesters, polyvinyl chloride and, preferably,polyolefins such as polyethylene and polypropylene, as well as paintsystems, also powder coating compositions, printing inks and coatingmaterials.

The novel compounds of formula I can be used in an amount of 0.01 to 30%by weight, preferably 0. 1 to 10% by weight, based on the high molecularweight organic material to be pigmented.

The pigmenting of the high molecular weight organic materials with thenovel compounds of formula I is conveniently effected by incorporating acompound of formula I by itself or in the form of a masterbatch in thesubstrates using roll mills, mixing or milling apparatus. The pigmentedmaterial is then brought into the desired final form by methods whichare known per se, conveniently by calendering, moulding, extruding,coating, casting or by injection moulding. It is often desirable toincorporate plasticisers into the high molecular weight compounds beforeprocessing in order to produce non-brittle mouldings or to diminishtheir brittleness. Suitable plasticisers are typically esters ofphosphoric acid, phthalic acid or sebacic acid. The plasticisers may beincorporated before or after blending the pigment salts of thisinvention into the polymers. To obtain different shades it is alsopossible to add fillers or other chromophoric components such as white,coloured or black pigments in any amount to the high molecular weightorganic materials in addition to the novel compounds of this invention.

For pigmenting paint systems, coating materials and printing inks, thehigh molecular weight organic materials and the novel compounds offormula I, together with optional additives such as fillers, otherpigments, siccatives or plasticisers, are finely dispersed or dissolvedin a common organic solvent or mixture of solvents. The procedure may besuch that the individual components by themselves, or also severalcomponents together, are dispersed or dissolved in the solvent andthereafter all the components are mixed.

When used for colouring, inter alia, polyvinyl chloride or polyolefinsor printing inks, the novel compounds of formula I have good allroundpigment properties, including good fastness to migration, light andweathering, and especially unexpectedly high fluorescence.

Of very great importance, however, is the entirely unexpected ease withwhich the soluble chromophores of this invention--even in the substratein which they have already been incorporated--can be converted to thecorresponding chromophore of formula A(H)_(x). This can be done in thesimplest manner, whether by thermal treatment (heating to thetemperature range from 50 to 400° C., preferably from 100 to 200° C. orlaser radiation), photolytic treatment (exposure to wavelengths belowe.g. 375 nm) or chemical treatment (with organic or inorganic acids orbases) of the solid materials, solutions or dispersions containing thenovel chromophores in organic or aqueous media, polymer solutions ormelts. These conversion methods can also be combined, thereby permittingthe coloration of paint systems, printing inks, especially for ink jetprinting, and plastics, also in fibre form, with unexpectedly enhancedproperties such as purity, colour strength, brilliance and transparency,as well as interesting applications in the analytical field.

It has even been found that the chemical treatment of specificchromophores of formula I with an organic or inorganic acid at 50 to180° C., preferably from 80 to 160° C., and subsequent cooling to about70 to 100° C., or the thermal treatment of said compounds by heating tothe temperature range from 180-350° C., can result in crystalmodifications of the corresponding chromophores of formula XVII.

The invention therefore additionally relates to a process for thecrystal modification of chromophores of formula XVII, comprising

a) the chemical treatment of a chromophore of formula I with an organicor inorganic acid at 50 to 180° C. and subsequent cooling, or

b) the thermal treatment of a chromophore of formula I in thetemperature range from 180 to 350° C.

The invention is illustrated in more detail by the following Examples.

EXAMPLE 1

To a mixture of 1.8 g (0.00576 mol) of quinacridone and 0.3 g (0.00246mol) of 4-dimethylaminopyridine in 90 ml of N,N-dimethylformamide areadded 6.0 g (0.0275 mol) of di-tert-butyldicarbonate. The resultantviolet suspension is stirred overnight at room temperature, with theexclusion of atmospheric moisture. The colour changes toyellowish-range. Afterwards, the reaction mixture is poured, withstirring, into 100 ml of distilled water. The yellow precipitate isisolated by filtration and the residue is washed with distilled waterand dried, affording 2.8 g (95% of theory) of the product of formula##STR23## Analysis:

¹ H-NMR(CDCl₃): 8.74 (s, 2H); 8.41 (d, 2H); 7.84 (d, 2H); 7.72 (t, 2H);7.38(t, 2H); 1.75 (s, 18H).

EXAMPLE 2

To a suspension of 10.31 g (0.0393 mol) of indigo and 2.79 g (0.0228mol) of 4-dimethylaminopyridine in 150 ml of N,N-dimethylformamide areadded, in two portions, 45.31 g (0.2076 mol) ofdi-tert-butyldicarbonate. The mixture is stirred for 20 hours at roomtemperature, during which time the colour changes from dark blue toviolet. The product is isolated by filtration and the residue is washedfirst with 20 ml of dimethyl formamide, then with distilled water, anddried, affording 9.79 g of a brilliant red solid. An additional 5.13 gof product is obtained by diluting the filtrate with distilled water.The total yield is 14.93 g (82.1% of theory) of a product of formula##STR24## Analysis:

¹ H-NMR(CDCl₃): 8.02 (d, 2H); 7.76 (d, 2H); 7.61 (t, 2H); 7.21 (t, 2H);1.62 (s, 18H).

EXAMPLE 3

To a mixture of 1.5 g (0.00337 mol) of the pigment of formula ##STR25##and 9.7 g (0.0444 mol) of di-tert-butyldicarbonate in 80 ml ofN,N-dimethylacetamide is added 0.18 g (0.00147 mol) of4-dimethylaminopyridine. The resultant suspension is stirred for 24hours at room temperature. The reaction mixture is then poured, withstirig, into 200 ml of distilled water. The yellow precipitate isisolated by filtration and the residue is washed with distilled waterand dried at room temperature under vacuum, affording 2.71 g (95% oftheory) of a product of formula ##STR26## Analysis:

¹ H-NMR(CDCl₃): 8.22 (d, 2H); 7.83 (d, 2H); 7.72 (t, 2H); 7.63 (t, 2H);7.56 (d, 2H); 7.42 (d, 2H); 1.45 (s, 36H).

EXAMPLE 4

To a mixture of 1.4 g (0.0037 mol) of a monoazopigment of formula##STR27## and 2.67 g (0.01221 mol) of di-tert-butyldicarbonate in 50 mlof N,N-dimethylacetamide are added 0.2 g (0.00164 mol) of4-dimethylaminopyridine. The reaction mixture is stirred for 48 hours atroom temperature, during which time an orange suspension forms. Theyellow precipitate is then isolated by filtration and the residue iswashed with a small amount of N,N-dimethylacetamide and afterwards withdistilled water and dried at room temperature under vacuum, affording0.67 g (31% of theory) of a product of formula ##STR28## Analysis:

¹ H-NMR(CDCl₃): 15.9 (s, br, 1H); 11.17 (s, br, 1H); 7.94 (d, 1H); 7.90(s, 1H); 7.85 (d, 1H); 7.64 (d, 1H); 7.06-7.04 (m, 2H); 2.65 (s, 3H);2.35 (s, 3H); 2.32 (s, 3H); 1.64 (s, 9H).

EXAMPLE 5

0.07 g of the product of Example 1 are heated in a test tube for 10minutes at 180° C. All analytical data obtained for the resultant violetpowder are in accord with those of the pure quinacridone of formula##STR29## The conversion yield is 99%.

EXAMPLE 6

0.07 g of the product of Example 3 are dissolved in 1 ml of acetone andthe solution is then added all at once to 1 ml of 33% HCl . Allanalytical data obtained for the resultant red powder are in accord withthose of the pure pigment of formula ##STR30## The conversion yield is99%.

EXAMPLES 7-10

In accordance with the general procedure described in Example 1, thecompounds of formula ##STR31## listed in the following Table can beobtained using corresponding dicarbonates.

    __________________________________________________________________________                              Reaction-                                             Example E Solvent time Yield Colour                                         __________________________________________________________________________      7                                                                                                               DMF 30 h 80% yellowish  orange             ##ST DMF 24 h 30% yellowish  orange                                             - 9                                                                              ##STR34##        DMF 16 h 80% yellowish  orange                            - 10                                                                                              ##S DMF 24 h 35% yellowish  orange                     __________________________________________________________________________     DMF = dimethyl formamide                                                 

EXAMPLE 11

To a suspension of 1.03 g of the product of Example 1 in 30 ml ofN,N'-dimethylforrnamide and 10 ml of water are added 4 ml oftrifluoroacetic acid. The mixture is heated to 105° C., stirred for 2hours at this temperature and then chilled on an ice-bath to 20° C. Theprecipitated pigment is isolated by filtration, washed with methanol andthen with water and dried at 60° C. under vacuum, affording 0.59 g ofred powder. The X-ray diffraction pattern is characterised by thefollowing diffraction lines:

    ______________________________________                                        Interplanar spacing                                                                         Two-fold hue angle                                                (d values in Å) (2 Θ) Relative intensity                          ______________________________________                                        15.0530       5.87         100                                                  7.5164 11.76 45                                                               5.5635 15.92 27                                                               4.0350 22.01 21                                                               3.7534 23.69 9                                                                3.2870 27.11 61                                                               2.9988 29.77 5                                                                2.3129 38.91 5                                                              ______________________________________                                         (β-modification of quinacridone).                                   

EXAMPLE 12

A mixture of 4.75 g of toluene-4-sulfonic acid and 100 ml of diphenylether is heated to 150° C. To the solution so obtained is then added asolution of 1.03 g of the product of Example 1 in 150 ml oftetrahydrofuran over 5 hours at 150° C. The tetrahydrofrran whichevaporates rapidly under these reaction conditions is condensed in aLiebig condenser and collected in a receiver. The reaction mixture isstited for a further 2 hours at 150° C. and then cooled to 60° C. Theprecipitated pigment is isolated by filtration, washed with methanol andafterwards with water and dried under vacuum at 60° C., affording 0.67 gof a red powder.

The The X-ray diffraction pattern is characterised by the followingdiffraction lines:

    ______________________________________                                        Interplanar spacing                                                                         Two-fold hue angle                                                (d-values in Å) (2Θ) Relative intensity                           ______________________________________                                        13.6841       6.45         100                                                  6.7972 13.01 43                                                               6.6153 13.37 52                                                               6.4440 13.73 84                                                               5.5678 15.91 5                                                                5.2536 16.86 10                                                               4.3559 20.37 14                                                               3.7526 23.69 14                                                               3.5632 24.97 11                                                               3.3796 26.35 66                                                               3.3583 26.52 55                                                               3.2065 27.80 7                                                                3.1306 28.49 7                                                                2.9534 30.24 6                                                                2.4576 36.53 5                                                                2.2135 40.73 7                                                              ______________________________________                                         (γ-modification of quinacridone).                                  

What is claimed is:
 1. A process for the preparation of a compound offormula

    A(B).sub.x,                                                (I),

wherein x is an integer from 1 to 4, A is the radical of a chromophoreof the quinacridone, anthraquinone, perylene, indigo, quinophthalone,isoindolinone, isoindoline, dioxazine, phthalocyanine or azo series,which radical contains x B groups attached to N-atoms, B is a group offormula ##STR36## or, when x is 2, 3 or 4, B may also be hydrogen, withthe proviso that at least one B is formula (II), (III) or (IV),m, n andp are each independently of one another 0 or 1, X is C₁ -C₁₄ alkylene orC₂ -C₈ alkenylene, Y is a group --V--(CH₂)_(q) --, Z is a group--V--(CH₂)_(r) --, V is C₃ -C₆ cycloalkylene, q is an integer from 1 to6, and r is an integer from 0 to 6, R₁ and R₂ are each independently ofthe other hydrogen, C₁ -C₆ alkyl, C₁ -C₄ alkoxy, halogen, CN, NO₂,unsubstituted phenyl or phenoxy or phenyl or phenoxy which aresubstituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy or halogen, Q is hydrogen,CN, Si(R₁)₃ ; a group C(R₅)(R₆)(R₇), wherein R₅, R₆ and R₇ are eachindependently of one another hydrogen or halogen and at least one of R₅,R₆ and R₇ is halogen; a group ##STR37## wherein R₁ and R₂ are as definedabove; a group SO₂ R₈ or SR₈, wherein R₈ is C₁ -C₄ alkyl;a groupCH(R₉)₂, wherein R₉ is unsubstituted phenyl or phenyl which issubstituted by C₁ -C₄ alkyl, C₁ -C₄ alkoxy or halogen; or a group offormula ##STR38## R₃ and R₄ are each independently of the otherhydrogen, C₁ -C₁₈ alkyl, a group ##STR39## wherein X, Y, R₁, R₂, m and nare as defined above, or R₃ and R4, together with the linking nitrogenatom, form a pyrrolidinyl, piperidinyl or morpholinyl radical,whichcomprises reacting a compound of formula

    A(H).sub.x                                                 (XVII)

wherein A and x are as defined above, in the desired molar ratio with adicarbonate of the formula

    B--O--B                                                    (XVIII)

or with a trihaloacetate of formula

    (R.sub.27).sub.3 C--B                                      (XIX),

or with an azide of formula

    BN.sub.3                                                   (XX),

or with a carbonate of formula

    B--OR.sub.28                                               (XXI),

or with an alkylidene-iminooxyformate of formula ##STR40## wherein B isas defined above, R₂₇ is chloro, fluoro or bromo, R₂₈ is C₁ -C₄ alkyl orunsubstituted phenyl or phenyl which is substituted by halogen, C₁ -C₄alkyl, C₁ -C₄ alkoxy or --CN, R₂₉ is --CN or --COOR₁₈, and R₃₀ isunsubstituted phenyl or phenyl which is substituted by halogen, C₁ -C₄alkyl, C₁ -C₄ alkoxy or --CN, in an aprotic solvent and in the presenceof a base as catalyst.
 2. A process according to claim 1, wherein x is 1or 2 and B is a group of formula ##STR41## and, if x is 2, may also beone hydrogen atom, and in formulae IV, V and VIm is 0 or 1, X is C₁ -C₄alkylene or C₂ -C₅ alkenylene, R₁ and R₂ are each independently of theother hydrogen, C₁ -C₄ alkyl, methoxy, chloro or NO₂, and Q is hydrogen,CN, CCl₃, a group ##STR42## SO₂ CH₃ or SCH₃, R₃ and R₄ are eachindependently of the other hydrogen, C₁ -C₄ alkyl or a group ##STR43##or R₃ and R₄, taken together, form a piperidinyl radical.
 3. A processaccording to claim 1, wherein x is 2 and B is a group of formula##STR44## and the number of groups B is two.
 4. A process according toclaim 1, wherein the aprotic solvent is selected from the groupconsisting of cyclic ethers, glycol mono- or diethers, dipolar aproticsolvents, halogenated aliphatic or aromatic hydrocarbons, benzene oralkyl-, or alkoxy- substituted benzenes and monocyclic aromaticN-heterocycles, and mixtures thereof.
 5. A process according to claim 4,wherein the aprotic solvent is selected from the group consisting oftetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethyleneglycol diethyl ether, diethylene glycol monomethyl ether, diethyleneglycol monoethyl ether, acetonitrile, benzonitrile,N,N-dimethylformamide, N,N-dimethylacetamide, nitrobenzene,N-methylpyrrolidone, trichloroethane, benzene, toluene, xylene, anisole,chlorobenzene, pyridine, picoline and quinoline, and mixtures thereof.6. A process according to claim 5, wherein the aprotic solvent istetrahydrofuran, N,N-dimethylformamide or N-methylpyrrolidone.
 7. Aprocess according to claim 1, wherein the base is selected from thegroup consisting of alkali metals and the hydroxides or carbonatesthereof, or alkali metal amides or alkali metal hydrides, alkaline earthmetal or alkali metal alcoholates which are derived from primary,secondary or tertiary aliphatic alcohols of 1 to 10 carbon atoms andorganic aliphatic, aromatic or heterocyclic N-bases, and mixturesthereof.
 8. A process according to claim 7, wherein the base is selectedfrom the group consisting of lithium, sodium or potassium metals and thehydroxides or carbonates thereof; lithium, sodium or potassium hydride;lithium, sodium or potasssium methylate, ethylate, n-propylate,isopropylate, n-butylate, sec-butylate, tert-butylate,2-methyl-2-butylate, 2-methyl-2-pentylate, 3-methyl-3-pentylate or3-ethyl-3-pentylate; diazabicyclooctene, diazabicycloundecene,4-dimethylaminopyridine, trimethylamine and triethylamine, and mixturesthereof.
 9. A process according to claim 8, wherein the base isdiazabicyclooctene, diazabicycloundecene or 4-dimethylaminopyridine. 10.A process according to claim 1, wherein the reaction is carried out inthe temperature range from 10 to 100° C.
 11. A process according toclaim 1, wherein the compound of formula XVII is reacted with adicarbonate of formula XVIII.